[Yap-users] yap-6.3 bug report

[Gong Su <go...@ho...>]

Hi, I'm not sure whether this is the right email for reporting yap bugs.

I'm trying to compile and run, on 64-bit Intel RedHat Linux, the latest version of yap-6.3 which I got from the git repository using

git clone git://git.code.sf.net/p/yap/yap-6.3

I found a couple of bugs:

1. In file C/qlyw.c, function save_int, the local variable v is declared as UInt (8 bytes) instead of int (4 bytes). As a result, the save_bytes call will only save the first 4 bytes of v. On a little endian machine, this happens to be correct. But on a big endian machine, you will get all 0s.

2. When configure yap with the option --enable-threads, you cannot do save_program. save_program will result in a segmentation fault like the following:

%
%
% YAP OOOPS: tried to access illegal address 0x18!!!!.
%
%
%
% PC: prolog:qsave_program/1 at clause 1 
%   Continuation: prolog:qsave_program/1 at clause 1 
Active Choice-Points:
prolog:$user_call(save_program(test),save_program(test))
prolog:$yes_no(save_program(test),?-)
prolog:$catch(_131266,user:$Error(_131266),_1048524)
prolog:[Segmentation fault

I have tried to do some debugging and it appears that there are predicate structures with garbage FunctorOfPred pointers. I added an fprintf line in save_program function:

fprintf(stderr, "%p %x %p\n", pp->FunctorOfPred, pp->FunctorOfPred->KindOfPE, pp->FunctorOfPred->NameOfFE);

and here are a few lines (among many): 

0x6a87c0 bb00 0x6a8790
0x6a8640 bb00 0x6a8610
0x6a84c0 6a84f0 (nil)
0x6a8370 6a83a0 0x726f5f
0x6a8220 bb00 0x6a8200
0x6a80b0 bb00 0x6a8090
0x6a7f40 bb00 0x6a7f20
0x6a7db0 bb00 0x6a7d80
0x6a7c10 bb00 0x6a7bf0
0x6a7aa0 6a7ad0 0x70666564
0x6a7950 6a7980 0x706665646e
0x6a7800 6a7830 0x6d6574737973
0x6a76b0 6a76e0 0x6d657473
0x6a7540 bb00 0x6a7520
0x6a73d0 bb00 0x68b7d0
0x695fa0 74c540 0x21
0x6a7140 bb00 0x6a7110
0x6a6fc0 bb00 0x6a6f90
0x6a6e40 bb00 0x6a6e10
0x6a6cc0 bb00 0x6a6c90
0x6a6b40 bb00 0x6a6b10
0x6a69c0 bb00 0x6a6990